Method for depositing metal oxide films

Abstract

A method for depositing a metal oxide film on a surface of a supporting body for the film, comprising the steps of: —providing a deposition chamber; —providing a pulsed beam of electrons and plasma in the deposition chamber; —supplying a supporting body in the deposition chamber, the supporting body having a deposition surface; —providing a target body made of a material which comprises the metal oxide in the deposition chamber, the target body having a target surface; —forming a plume of metal oxide ablated from the target surface by means of the impact of the pulsed beam of electrons and plasma against the target surface; and —depositing a metal oxide film on the deposition surface by means of the contact of the plume with the deposition surface.

1 . A method for depositing a metal oxide film on a surface of a supporting body for said film, comprising the steps of:
 providing a deposition chamber;   providing a pulsed beam of electrons and plasma in said deposition chamber;   supplying a supporting body in said deposition chamber, said supporting body having a deposition surface;   providing a target body made of a material which comprises said metal oxide in said deposition chamber, said target body having a target surface;   providing a plume of metal oxide ablated from said target surface by means of the impact of said pulsed beam of electrons and plasma against said target surface; and   depositing a metal oxide film on said deposition surface by means of the contact of said plume with said deposition surface.   
     
     
         2 . The method according to  claim 1 , wherein said metal oxide is a transparent conducting oxide, particularly a metal oxide selected from the group constituted by zinc oxide and zinc oxide doped with aluminum, or lithium or other dopants. 
     
     
         3 . The method according to  claim 1 , wherein said supporting body is a supporting body made of a transparent material, or a non transparent material. 
     
     
         4 . The method according to  claim 1 , wherein said supporting body is a supporting body which is flexible or rigid. 
     
     
         5 . The method according to  claim 1 , wherein said supporting body is a body made of solid inorganic material. 
     
     
         6 . The method according to  claim 5 , wherein said supporting body is made of a material selected from the group constituted by glass, quartz, CdS, ZnSe, metals, and inorganic semiconductors. 
     
     
         7 . The method according to  claim 1 , wherein said supporting body is a body made of solid organic material. 
     
     
         8 . The method according to  claim 7 , wherein said supporting body is made of a material selected from the group constituted by polymers such as polyesters, polyolefines, polyimides, phenolic resins, polyanhydrides, conducting polymers, conjugated polymers, fluoropolymers, silicone rubbers, silicone polymers, biopolymers, copolymers, block copolymers such as polycarbonate, PTFE, PET, PNT, PEDOT, polyaniline, polypyrrole, polythiophenes, polyparaphenylenes (PPV), polyfluorenes, and molecular solids like molecular semiconductors, molecular crystals, molecular thin films, molecular dyes, such as AlQ3, thiophene oligomers, PPV oligomers, pentacene, tetracene, rubrene, NPB, fullerenes, carbon nanotubes and fullerides. 
     
     
         9 . The method according to  claim 1 , wherein said electron and plasma beam has a pulsed energy from 500 keV to 50 keV, particularly from 5 keV to 20 keV. 
     
     
         10 . The method according to  claim 1 , wherein a pressure from 10 −6  to 10 −2  mbar, preferably from 10 −5  to 5×10 −3  mbar, is maintained in said deposition chamber. 
     
     
         11 . The method according to  claim 1 , wherein in said deposition chamber there is a working gas selected among the group constituted by oxygen, argon, nitrogen and mixtures of methane and argon, hydrogen and argon, boranes, diboranes and ammonia. 
     
     
         12 . The method according to  claim 1 , wherein said beam of electrons and plasma is a pulsed beam of electrons and plasma generated with a frequency from 0.1 Hz to 500 Hz, particularly from 1 Hz to 19 Hz. 
     
     
         13 . The method according to  claim 1 , wherein said pulsed beam of electrons and plasma is a beam of electrons and plasma generated by using an average current from 1 mA and 50 mA, particularly from 1 to 5 mA. 
     
     
         14 . The method according to  claim 1 , wherein said pulsed beam of electrons and plasma is a beam of electrons and plasma generated by using a potential difference between an anode and a cathode from 500 V to 50 ke V, particularly from 12 to 18 kV. 
     
     
         15 . The method according to  claim 1 , wherein said target surface and said deposition surface are arranged at a mutual distance from 5 mm to 500 mm. 
     
     
         16 . The method according to  claim 5 , wherein said support has a temperature comprised between ambient temperature and 550° C. 
     
     
         17 . The method according to  claim 7 , wherein said support has a temperature comprised between ambient temperature and 350° C. 
     
     
         18 . The method according to  claim 1 , wherein it further comprises the step for adjusting a distance between said target surface and said deposition surface. 
     
     
         19 . The method according to  claim 1 , wherein it further comprises the step for adjusting the temperature of said supporting body. 
     
     
         20 . The method according to  claim 1 , wherein said target body is subjected to a rotary motion during said deposition step. 
     
     
         21 . The method according to  claim 1 , wherein said deposition supporting body is subject of rotary motion during said deposition step. 
     
     
         22 . The method according to  claim 1 , wherein said supporting body and said target body are positioned within said deposition chamber so that said plume makes contact with said deposition surface. 
     
     
         23 . A method for depositing a film of a metal oxide doped with a doping agent on a surface of a supporting body for said film, comprising the steps of:
 providing a deposition chamber;   providing a first and a second pulsed beam of electrons and plasma in said deposition chamber;   supplying a supporting body in said deposition chamber, said supporting body having a deposition surface;   providing in said deposition chamber a first and a second target body, said first target body being made of a material which comprises said metal oxide, said second target body being made of a material which comprises said doping agent, said first target body having a first target surface and said second target body having a second target surface;   providing a plume of metal oxide ablated from said first target surface by means of the impact of said first pulsed beam of electrons and plasma against said first target surface, and a plume of said doping agent ablated from said second target surface by means of the impact of said second pulsed beam of electrons and plasma against said second target surface; and   depositing simultaneously said metal oxide and said doping agent on said deposition surface by means of the contact of said plume of metal oxide and of said plume of doping agent with said deposition surface, thereby a film of said metal oxide doped with said doping agent is obtained on said deposition body.   
     
     
         24 . The method according to  claim 23 , wherein said metal oxide is type-p ZnO and said doping agent is a Li containing compound, as Li2O. 
     
     
         25 . The method according to  claim 23 , wherein said metal oxide is ZnO and said doping agent comprises magnetic species. 
     
     
         26 . A metal oxide film which can be obtained by deposition on a surface of a supporting body by means of the method according to  claim 1 .